[jOOQ/jOOQ#11250] Add ParseContext.languageContext()

This includes:

- [jOOQ/jOOQ#10243] Added nullability annotations to ParseContext
- [jOOQ/jOOQ#10243] Document exceptions thrown from ParseContext

jOOQ/src/main/java/org/jooq/LanguageContext.java

@@ -0,0 +1,80 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Other licenses:
+ * -----------------------------------------------------------------------------
+ * Commercial licenses for this work are available. These replace the above
+ * ASL 2.0 and offer limited warranties, support, maintenance, and commercial
+ * database integrations.
+ *
+ * For more information, please visit: http://www.jooq.org/licenses
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ */
+package org.jooq;
+
+/**
+ * The current language context of some {@link ParseContext} or
+ * {@link RenderContext}.
+ * <p>
+ * This can be useful to help distinguish between ways to generate SQL, e.g.:
+ * <ul>
+ * <li>whether <code>CAST</code> expressions are allowed to generate length,
+ * precision, and scale</li>
+ * <li>whether <code>DELETING</code> and similar "magic" identifiers are from a
+ * <code>TRIGGER</code>, or not</li>
+ * </ul>
+ *
+ * @author Lukas Eder
+ */
+public enum LanguageContext {
+
+    /**
+     * A SQL query, including DDL to create procedural elements.
+     */
+    QUERY,
+
+    /**
+     * The body of a stored procedure.
+     */
+    PROCEDURE,
+
+    /**
+     * The body of a stored function.
+     */
+    FUNCTION,
+
+    /**
+     * The body of a trigger.
+     */
+    TRIGGER,
+
+    /**
+     * The body of an anonymous block.
+     */
+    BLOCK
+}